The aging process is most visibly depicted by the development of dependent skin laxity. This life long process may become evident as early as the third decade of life and will progressively worsen over subsequent decades. Histological research has shown that dependant stretching or age related laxity of the skin is due in part to progressive dermal atrophy associated with a reduction of skin tensile strength. When combined with the downward force of gravity, age related dermal atrophy will result in the two dimensional expansion of the skin envelope. The clinical manifestation of this physical-histological process is redundant skin laxity. The most affected areas are the head and neck, upper arms, thighs, breasts, lower abdomen and knee regions. The most visible of all areas are the head and neck. In this region, prominent “turkey gobbler” laxity of neck and “jowls” of the lower face are due to an unaesthetic dependency of skin in these areas.
Plastic surgery procedures have been developed to resect the redundant lax skin. These procedures must employ long incisions that are typically hidden around anatomical boundaries such as the ear and scalp for a facelift and the inframammary fold for a breast uplift (mastopexy). However, some areas of skin laxity resection are a poor tradeoff between the aesthetic enhancement of tighter skin and the visibility of the surgical incision. For this reason, skin redundancies of the upper arm, suprapatellar knees, thighs and buttocks are not routinely resected due to the visibility of the surgical scar.
The frequency and negative societal impact of this aesthetic deformity has prompted the development of the “Face Lift” surgical procedure. Other related plastic surgical procedures in different regions are the Abdominoplasty (Abdomen), the Mastopexy (Breasts), and the Brachioplasty (Upper Arms). Inherent adverse features of these surgical procedures are post-operative pain, scarring and the risk of surgical complications. Even though the aesthetic enhancement of these procedures is an acceptable tradeoff to the significant surgical incisions required, extensive permanent scarring is always an incumbent part of these procedures. For this reason, plastic surgeons design these procedures to hide the extensive scarring around anatomical borders such as the hairline (Facelift), the inframmary fold (Mastopexy), and the inguinal crease (Abdominoplasty). However, many of these incisions are hidden distant to the region of skin laxity, thereby limiting their effectiveness. Other skin laxity regions such as the Suprapatellar (upper-front) knee are not amendable to plastic surgical resections due to the poor tradeoff with a more visible surgical scar.
More recently, electromagnetic medical devices that create a reverse thermal gradient (i.e., Thermage) have attempted with variable success to tighten skin without surgery. At this time, these electromagnetic devices are best deployed in patients with a moderate amount of skin laxity. Because of the limitations of electromagnetic devices and potential side effects of surgery, a minimally invasive technology is needed to circumvent surgically related scarring and the clinical variability of electromagnetic heating of the skin. For many patients who have age related skin laxity (neck and face, arms, axillas, thighs, knees, buttocks, abdomen, bra line, ptosis of the breast), fractional resection of excess skin could augment a significant segment of traditional plastic surgery.
Even more significant than aesthetic modification of the skin envelope is the surgical management of burns and other trauma related skin defects. Significant burns are classified by the total body surface burned and by the depth of thermal destruction. First-degree and second-degree burns are generally managed in a non-surgical fashion with the application of topical creams and burn dressings. Deeper third-degree burns involve the full thickness thermal destruction of the skin. The surgical management of these serious injuries involves the debridement of the burn eschar and the application of split thickness grafts.
Any full thickness skin defect, most frequently created from burning, trauma, or the resection of a skin malignancy, can be closed with either skin flap transfers or skin grafts using current commercial instrumentation. Both surgical approaches require harvesting from a donor site. The use of a skin flap is further limited by the need of to include a pedicle blood supply and in most cases by the need to directly close the donor site.
The split thickness skin graft procedure, due to immunological constraints, requires the harvesting of autologous skin grafts, that is, from the same patient. Typically, the donor site on the burn patient is chosen in a non-burned area and a partial thickness sheet of skin is harvested from that area. Incumbent upon this procedure is the creation of a partial thickness skin defect at the donor site. This donor site defect is itself similar to a deep second-degree burn. Healing by re-epithelialization of this site is often painful and may be prolonged for several days. In addition, a visible donor site deformity is created that is permanently thinner and more de-pigmented than the surrounding skin. For patients who have burns over a significant surface area, the extensive harvesting of skin grafts may also be limited by the availability of non-burned areas.
For these reasons, there is a need in the rapidly expanding aesthetic market for instrumentation and procedures for aesthetic surgical skin tightening. There is also a need for systems, instruments or devices, and procedures that enable the repeated harvesting of skin grafts from the same donor site while eliminating donor site deformity.